Okay, I just want everyone to appreciate the lengths I will go to for realism in my book. I have been researching veins and arteries of the neck this morning, and is seems that the jugular vein and carotid artery lay side-by-side in the neck (the vein appears to be more on top). Apparently it takes a lot of measuring and mathematical calculations (sometimes aided by ultrasound) for medical professionals to tell them apart, so they can tap one or the other. Which means my vampires are not going to be that accurate; they may wind up hitting either one. Although, given that the vein is closer to the top, that’s probably what they’ll hit when they bite. Which is better from a medical standpoint, because they would be taking blood that’s leaving the brain, not blood that’s going into it. It’s always important to feed the brain. As I know all too well from my late grandfather’s problems with blockages in his carotid arteries, a lack of bloodflow to the brain can cause hallucinations, confusion and fainting.
http://www.psy.cmu.edu/faculty/klatzky/09Wang_etal.pdf Mmm, interesting stuff for a Saturday morning.
I finally found what I was looking for: the IJV (don’t I sound technical?) is 1.5cm beneath the skin, on average, which is slightly more than half an inch. That doesn’t sound very deep, until you start thinking about teeth long enough to puncture that deep. And you don’t measure the entire length of the tooth, but from where it extends below the other teeth (which don’t break the skin). But, when you bite down on anything—especially soft tissue—it compresses, so I’m thinking the teeth don’t actually need to be that long in order to work. Which is good, because that would make for some damn long fangs otherwise.
More thought and experimentation on this to follow.